Don’t write terms and conditions, write Community Laws.
Make them interesting, worth reading. Update them every 4 months. Invite members to help. Make it a process of converting unwritten rules, into written ones.
Make it a process of removing laws. If you have a law that everyone abides to (“please don’t self-promote your company”), take pride in removing it. It becomes part of an unwritten code.
Be proud that your community can run on as few laws as possible. It will gel your community together.